<!-- 轮播图基础结构 -->
<template>
    <div class='xtx-carousel' @mouseenter="stop()" @mouseleave="start()">
        <ul class="carousel-body">
            <!-- fade 激活图片 -->
            <li class="carousel-item" v-for="(item, i) in silders" :key="i" :class="{ fade: index === i }">
                <RouterLink v-if="item.hrefUrl" to="item.hrefUrl">
                    <img :src="item.imgUrl" alt="">
                </RouterLink>
                <div v-else class="slider">
                    <RouterLink v-for="goods in item" :key="goods.id" :to="`/product/${goods.id}`">
                        <img :src="goods.picture" alt="">
                        <p class="name ellipsis">{{ goods.name }}</p>
                        <p class="price">&yen;{{ goods.price }}</p>
                    </RouterLink>
                </div>
            </li>
        </ul>
        <a @click="toogle(-1)" href="javascript:;" class="carousel-btn prev"><i
                class="iconfont icon-angle-left"></i></a>
        <a @click="toogle(1)" href="javascript:;" class="carousel-btn next"><i
                class="iconfont icon-angle-right"></i></a>
        <!-- 指示器 active激活 -->
        <div class="carousel-indicator">
            <span @click="index=i" v-for="(item, i) in silders" :key="i" :class="{ active: index === i }"></span>
        </div>
    </div>
</template>
  
<script>
import { onUnmounted, ref, watch } from 'vue'
export default {
    name: 'XtxCarousel',
    props: {
        silders: {
            type: Array,
            default: () => []
        },
        duration: {
            type: Number,
            default: 3000
        },
        antoPlay: {
            type: Boolean,
            default: true
        }
    },
    setup(props) {
        // 设置默认索引
        const index = ref(0)
        // 自动播放
        let timer = null
        const autoPlayFn = () => {
            clearInterval(timer)
            timer = setTimeout(() => {
                index.value++

                if (index.value >= props.silders.length) {
                    index.value = 0
                }
            }, props.duration)
        }
        watch(() => index.value, () => {
            // 有数据 并且开启了自动播放，才调用自动播放
            if (props.antoPlay) {
                autoPlayFn()
            }
        }, { immediate: true })
        // 鼠标进入轮播 计时停止
        const stop = () => {
            if (timer) clearInterval(timer)
        }
        // 鼠标离开轮播 计时开始
        const start = () => {
            if (props.silders.length && props.antoPlay) {
                autoPlayFn()
            }
        }
        // 左右按钮切换
        const toogle = (step) => {
            const newIndex = index.value + step
            if (newIndex >= props.silders.length) {
                index.value = 0
            } else if (newIndex < 0) {
                index.value = props.silders.length - 1
            } else {
                index.value = newIndex
            }

        }
        // 销毁计时器
        onUnmounted(() => {
            clearInterval(timer)
        })
        return {
            index,
            stop,
            start,
            timer,
            toogle
        }
    }
}
</script>
<style scoped lang="less">
.xtx-carousel {
    width: 100%;
    height: 100%;
    min-width: 300px;
    min-height: 150px;
    position: relative;

    .carousel {
        &-body {
            width: 100%;
            height: 100%;
        }

        &-item {
            width: 100%;
            height: 100%;
            position: absolute;
            left: 0;
            top: 0;
            opacity: 0;
            transition: opacity 0.5s linear;

            &.fade {
                opacity: 1;
                z-index: 1;
            }

            img {
                width: 100%;
                height: 100%;
            }

            // 轮播商品
            .slider {
                display: flex;
                justify-content: space-around;
                padding: 0 40px;

                >a {
                    width: 240px;
                    text-align: center;

                    img {
                        padding: 20px;
                        width: 230px !important;
                        height: 230px !important;
                    }

                    .name {
                        font-size: 16px;
                        color: #666;
                        padding: 0 40px;
                    }

                    .price {
                        font-size: 16px;
                        color: @priceColor;
                        margin-top: 15px;
                    }
                }
            }
        }

        &-indicator {
            position: absolute;
            left: 0;
            bottom: 20px;
            z-index: 2;
            width: 100%;
            text-align: center;

            span {
                display: inline-block;
                width: 12px;
                height: 12px;
                background: rgba(0, 0, 0, 0.2);
                border-radius: 50%;
                cursor: pointer;

                ~span {
                    margin-left: 12px;
                }

                &.active {
                    background: #fff;
                }
            }
        }

        &-btn {
            width: 44px;
            height: 44px;
            background: rgba(0, 0, 0, .2);
            color: #fff;
            border-radius: 50%;
            position: absolute;
            top: 228px;
            z-index: 2;
            text-align: center;
            line-height: 44px;
            opacity: 0;
            transition: all 0.5s;

            &.prev {
                left: 20px;
            }

            &.next {
                right: 20px;
            }
        }
    }

    &:hover {
        .carousel-btn {
            opacity: 1;
        }
    }
}
</style>